'heterocotyly' originates from Greek via New Latin: from Greek 'heteros' meaning 'other, different' and Greek 'kotylion' (a diminutive of 'kotyle') meaning 'cup' or 'hollow' (used in botanical Latin to form 'cotyledon').

'heterocotyly' formed in New/Modern Latin as a compound of 'hetero-' + 'cotyl(ē)on' (cotyledon), entered English botanical usage as 'heterocotyly' to describe unequal cotyledons in seedlings.

Initially formed from elements meaning 'different' + 'cup' (referring to cotyledons), it came to denote specifically the condition of having unequal seed leaves (cotyledons) in botanical contexts.